NL8403739A - Catalyst contg. metals of groups VIB and VIII - of use for hydrotreating oils is prepd. by impregnating alumina with an ammoniacal soln. of the metals - Google Patents

Abstract

A catalyst containing (a) an oxide and/or sulphide of a Group VIB metal, (b) an oxide and/or sulphide of a Group VIII metal, and (c) transition alumina, has an oxygen chemisorption activity of at least 185 micromoles oxygen/ g catalyst. A catalyst contg. a Gp VIII metal, a VIB metal and carrier material is prepd. by impregnating shaped particles contg. transition alumina with an ammoniacal soln. (A) of the metals, evaporating to dryness, calcining and sulphiding; (A) has initial pH 10.5-13, pref. 11.0-12.5.

Description

ί _ _ X

Catalyst suitable for desulphurisation and preparation of this catalyst

The application relates to catalysts for treating petroleum and fractions thereof with hydrogen (so-called hydrotreating) in order to desulphurise (HDS = hydropulphurization), nitrogen (HDN) and hydrogenate, ie organic sulfur compounds in hydrogen sulfide, organic nitrogen compounds in ammonia and unsaturated compounds are converted to saturated ones.

Such catalysts are also used to remove oxygen and / or metals (HDO or HDM, respectively) and for hydrocracking.

Such catalysts are also used in the processing of synthetic crude oil (syn-15 crudes) and "coal liquids".

Depending on the desired improvement in the petroleum (fraction), one or more reaction types as mentioned above-20 will be allowed to proceed (e.g. only HDS or HDS and HDN). This desired selectivity in the "hydrotreating" process can be obtained by selecting the appropriate process conditions and by selecting an appropriate catalyst.

25

These catalytic conversions are widely used industrially in "upgrading" and refining petroleum fractions, and there is therefore a great need for suitable catalysts of varying selectivity and high activity. Often combinations of metal sulfides of Group VI are used for this purpose

(B) and Group VIII on a support. As a rule, these catalysts are sulfided in situ and are therefore offered and traded in the oxidic phase. As carrier 8403739 * R 7011 (R) 2, a transition alumina, in particular gamma alumina, is used. Sometimes - for special applications - it is advantageous to use amorphous and / or crystalline aluminum silicates as a carrier. As a rule, the carrier is used as preformed particles, i.e. as extrudate, spheres, rods, etc.

More particularly, combinations of cobalt or nickel on the one hand, and / or molybdenum or tungsten on the other, are often applied to alumina or the like.

Catalysts of this type and their preparation are known in the art. For example, US-A-4 399 058 (Gulf Research) discloses similar catalysts, in which alumina is impregnated with an ammonia solution of nickel sulfate and a molybdenum salt. According to column 9, lines 14-32, it is impregnated with an ammoniacal solution of pH 8.4 (in the absence of the molybdate, the pH would have been 10).

20 *

GB-A-1 368 795 (Pechiney-Saint Gobain) also discloses similar catalysts, mainly using ammoniacal nickel nitrate solutions for impregnation.

25 GB 1 408 760 (Shell Int. Research Me) likewise discloses such catalysts, mainly using ammoniacal solutions such as nitrates, chlorides, carbonates, formates and acetates; predominantly 30 nitrates are used.

Finally, there is NL-A-8303538 (Nippon Oil), in which it is disclosed that an ammoniacal solution of the metal carbonate, together with organic acids, such as tartaric acid, malic acid and the like, is used for impregnation.

R 8403739 3

It has now been found that the cobalt molybdenum catalyst is active for HDS but has little activity for HDN, while the cheaper nickel molybdenum catalyst is very active for HDN, but little active for HDS * The 5 nickel tungsten catalyst is mainly active for hydrogenating aromatics and otherwise moderately active for HDS and HDN. The nickel-molybdenum catalyst is also used for this application.

There is therefore a need for a catalyst, preferably based on the cheaper nickel, which combines high HDS with high HDN and high aromatics hydrogenation activity. In particular, there is a need for catalysts with a low metal content or optionally "normal" metal content with markedly improved catalytic properties.

Normally, these catalysts contain 0.5-20, preferably 1-10 wt.%, Based on the Group VIII metal catalyst, and 2.5-60, preferably 5-20 wt.%, Of the metal of Group VI, while their ratio is between 40: 1 and 1: 3 (Group VIII to Group VI).

It has now been found that catalysts with excellent selectivity and activity can be prepared by impregnating preformed alumina particles with an ammoniacal metal solution with a particularly high pH value, namely between 10.5 and 13, preferably between 11.0 and 13 , and then the impregnated alumina particles are evaporated, calcined and sulfided to dryness.

It is believed that the better properties are associated with reduced formation of a Group VI metal, especially nickel aluminate, which is catalytically inactive. In addition, at the higher pH

O

T 8403739 * i Λ = 5 R 7011 (R) 4 value to a lesser extent polymer molybdate is formed and nickel molybdates with an atomic nickel / molybdate ratio of about 1: 1 would be formed which are catalytically very active.

5

During the evaporation of dryness of the impregnated carrier material, mainly ammonia gas escapes, as a result of which the pH drops. However, it is expected from the theory that in the process of the present invention it is rarely set to values below 8.5-9.0.

If the ammonia metal solution contains significant amounts of anions of stronger acids, in particular of strong mineral acids, such as sulfuric acid and nitric acid, then these can be expected to effect a significant decrease in pH, not only during evaporation to dryness, but also already in the initial pH. It is therefore recommended that the impregnation liquid (in the present case the ammoniacal metal solution) be wholly or practically completely free of anions derived from stronger acids than carbonic acid, and in particular be free, or practically free, of anions. of strong mineral acids. Preferably, therefore, the ammonia metal solution is prepared by dissolving finely divided Group VIII metal in an ammonium carbonate solution in ammonia under oxygen passage. The ammonium carbonate solution in ammonia is prepared in a practical manner by passing carbonic acid through a solution of ammonia.

It will be clear that in this way a catalyst according to the invention can be obtained which is practically free of anions derived from stronger acids, in particular free of mineral acids.

O 8403739 \ i * 5 R 7011 (R)

After the carrier has been impregnated with the above-mentioned ammonia solution at least once, it is dried and calcined. Drying generally takes place at temperatures between 50 and 150 ° C, after which calcining is carried out at a temperature usually between 150 and 550 ° C. The catalyst in the form of the oxidic phase thus obtained is ready to be placed on the market.

It goes without saying that the original shape and the properties of the carrier material are largely retained, but additives can, for example, influence the porosity.

During the impregnation with solutions of Group VI and / or Group VIII metal salts in ammonia, but also thereafter or before, one or more promoters may be incorporated in the catalyst. Suitable promoters are, for example, metals or oxides, such as calcium, zinc, barium, etc. A promoter, such as 2Q5, is to be added afterwards.

Before the catalyst can be used, it still has to be sulphided. This sulfidation can take place by contacting the catalyst with a sulfur-containing compound, for example hydrogen, dust and hydrogen sulfide, carbon disulfide or a mercaptan. This can be done excellently in situ, sometimes with a sulfur-containing hydrocarbon. The oxide 30 present is wholly or largely converted into sulfide.

After the catalyst has been sulfided, it is ready for use. A promoter can also be added now.

The "hydrotreatment" according to the invention takes place with a catalyst as described above, depending on the petroleum (fraction) and the catalyst, as well as the desired conversions carried out under very different conditions.

The operating pressure may vary between 10,110 ^ Pa and 300,10 ^ Pa, hydrogen / oil (fraction) 5 ratios between 0-2500 m ^ / m ^. The reaction temperature varies between 250 and 500®C.

The catalyst properties are determined in the present application according to a standard test procedure 10, which is described below.

Test procedure: Determination of catalytic activity.

The hydrogenolytic activity of catalysts is determined by the catalyzed reaction of organic sulfur and nitrogen compounds with hydrogen to form hydrogen sulfide (H2S) and ammonia (NH3) together with hydrocarbons.

The hydrogenation activity of catalysts is determined from the catalyzed hydrogenation of cyclohexene.

The test is carried out in a heated tube reactor with an internal diameter of 12 mm, equipped with a 25 "thermowell" with 5 temperature readings, 3 of which are used to measure the temperature at the top, middle and bottom of the catalyst bed.

A synthetic feed consisting of 5% thiophene, 1.6% pyridine, 5% cyclohexene (optional) and toluene (balance up to 100%) is pumped at a constant speed, passes a preheating coil, raising the temperature to the specified reaction temperature, and then passed over the catalyst bed together with hydrogen.

Q 8403739 7 R 7011 [B)

The catalyst bed consists of 3 grams of ground and sieved catalyst particles with a particle diameter between 0.25 and 1.0 mm, on which a bed of 3g silicon carbide is applied. The silicon carbide with a particle size distribution identical to that of the catalyst serves as a preheating zone and ensures good mixing of the feed with hydrogen. The catalyst is sulfurized with 10% H 2 S in H 2 before starting the reaction. The sulfurization and test conditions are given in Table 1.

Table 1

Sulfurization conditions 15

Temperature: 400 * C Duration s 1 h Gas s 10% H2S in H2

Flow s 500 ml H2s / H2 per minute 20 Pressure s 10 ^ Pa

Test conditions k

Food s 5% thiophene, 1.6% pyridine, 5% cyclohexene 25 (optional) in toluene.

Catalyst: 3 g of broken catalyst particles 0.25 - 1.0 mm

Power supply: 0-.4 ml / rain. (liquid)

Hydrogen: 100 ml / min.

30 Temperature s 12 h at 325eC, followed by 8 h at 375 ° C Pressure s 10.105Pa.

The reaction product is analyzed continuously "online" using GLC techniques.

i * Q 8403739

i 'C

8 R 7011 (R)

The catalytic activity of a catalyst is determined by the desulfurization of thiophene at 325 ° C 12 hours after the start of the test and expressed according to; % HDS (desulfurization) = j-le cthio.j χ iqo% 5 C ° thio.

Cethio = thiophene concentration in the diet

Cthio = thiophene concentration in the reaction product.

The activity of a catalyst in the dedusting agent of pyridine is determined 20 hours after starting the experiment at 375 ° C and expressed according to:% HDN (dedusting agent) = Cpyr + Cpipj χ iq0% 15 C * pyr

Cepyr = pyridine concentration in the diet.

C pyr = pyridine concentration in the reaction product.

C pip * piperidine concentration in the reaction product, 20

The hydrogenation activity on cyclohexene is expressed in an identical manner as described above for the Ijydrogenogenolytic activity on thiophene and pyridine.

25 For hydrogenolysis and hydrogenation, the relative • activity is expressed relative to a reference catalyst according to: RGA * —k_ χ 100% _ in (cthio / Cethio) 30 Kref ln (Cref / c ° thio) thio (desulfurization) ln ( Cpyr + Cpip / C ° pyr) _ 35 ln (Crefpyr + Cr®fpip / Cepyr) \ 84037 ^ 0 \ ^ (dedusting) 9 * In (Ccyclohex / C0cyclohex)

In (Creioyclohex / Cecyclohex) (hydrogenation} 5 RGA = relative weight activity

Cre ^ thio = thiophene concentration in the reaction mixture for the reference catalyst Cre ^ pyr, Cre ^ pip., Cre ^ cyclohex = as above, 10 but for pyridine, piperidine and cyclohexene k * reaction rate constant kre ^ = reaction rate constant for reference catalyst 15

Two widely used industrial catalysts are used as reference catalyst, with the following metal loads.

20 Commercial% M0O3% NiO% CoO catalyst_ A (USA) 20.6 5.0 B (Eur) 15.7 - 4.6 25__

The invention is illustrated by the following Examples.

O

V 8403 739 R 7011 (R) 10

Example I

A. Preparation of Ammonia Ni Solution 5 NiCO 3-49% Ni (450 g) together with ammonium carbamate was dissolved in 2 L of 25% ammonia by stirring the mixture at 50 ° C under reflux of ammonia for 3 hours. This solution has a pH of 12.1 and contains 0.1347 g NiO / ml.

10

B. Preparation of Catalyst I.

80 g of a preformed alumina (internal surface 270 m2 / g, pore volume 0.7 ml / g, 1.6 mm extrudate) was impregnated with a solution consisting of: 25 ml of the ammoniacal nickel solution from Example I A.

23.6 g (NH4) 6 Mo7024. 4 H 2 O 20 made up to 120 ml with water.

, »

60 ml of this solution was taken up by the catalyst support. The catalyst was dried at 120 ° C and then calcined, raising the temperature to 450 ° C at 5 ° C per minute and then kept at 450 ° C for 2 hours.

The finished catalyst I contained 1.8% Nio and 10.8% M0O3. 30

Example II

A. Preparation of ammonia Ni solution * * 35 Preparation of an ammonia nickel solution by dissolving finely divided nickel powder (200 g with an average particle size of 50 yum) in 6.3 L aqueous R 7011 (R) * 11 ammonia / ammonium bicarbonate with NH4HCO3 / Ni = 2 (mol / mol) and NH3 / Ni = 7 (raol / mol).

At 50 ° C, 80 l of air per hour was passed under cooling for 8 hours. This solution has a pH of 10.8 and a nickel content of 0.0402 g Nio / ml.

B. Preparation of Catalyst II

20 g of a preformed support (internal surface 260 m ^ 10 g, pore volume 0.7 ml / g, 1.5 mm extrudate) was impregnated with a solution consisting of: 70 g (NH4) g Μο ^ Ο24 4 H2O 3.3 ml 25% ammonia solution 10 in 24.7 ml demineralized water.

14 ml of this solution was taken up by the catalyst support. The impregnated support was dried in an air stream at 75 ° C overnight. Then, the molybdenum oxide-impregnated catalyst support was impregnated with the ammoniacal nickel solution prepared according to Example II A. The catalyst was dried overnight at 75 ° C in an air stream and then calcined as in Example I.

The finished catalyst II contained 1.7% NiO and 12.1% MOO3.

25

Example III

Similar to Example I, however, the impregnation was carried out with a toe solution consisting of: 30 - 86 ml of the ammonia nickel solution from Example I A.

S 54.4 g {nh4) 6mo7o24. 4h2o I 8403739 R 7011 (R) 12 made up to 140 ml.

The finished catalyst III contained 4.9% NiO and 20.2% MOO3.

5

Example IV

Preparation of an ammonia cobalt solution. 10 Basic cobalt carbonate (O2 (0Η) 2002 .nH2 O7 45.5% Co), 77 g and ammonium carbaminate 164 g in 500 ml 25% ammonia were heated to 45 ° C for 3 hours, with ammonia reflux. Then 15 g of ammonium bicarbonate was added and the mixture was stirred at 45 ° C under reflux of ammonia for 16 hours.

This solution has a pH of 12 and contains 0.081 g of CoO per ml.

80 g of a preformed alumina support (internal surface 260 m2 / g, pore volume 0.7 ml / g, 1.6 mm extrudates) was impregnated with a solution consisting of 46.8 ml of the ammonia cobalt solution 17.6 g ( NH4) 6 Mo7024. 4H20 supplemented to 120 ml.

65 ml of this solution was taken up by the catalyst support during the impregnation.

The catalyst was dried at 120 ° C overnight and then calcined, raising the temperature to 500 ° C by 5eC per mifauut and then kept at 500 ° C for 2 hours.

Q 8403739 \ 13

The finished Catalyst IV contained 2.3% CoO and 8.6% M0O3.

Examples V-VIII 5

Catalysts X through IV were tested according to the test procedure described above. The results are shown in the Table below.

10 Table II

Composition and relative activities of the catalysts described in the Examples. Kat. wt%%% M RGA (S) a RGA (N) b RGA {H) a Ref.

NiO COO M0O3 Cat.

I 1.8 - 10.8 140 150 160 A.

II 1.7 - 12.1 110 100 160 A.

20 III 4.9 - 20.2 160 150 - A

IV - 2.3 8.6 155 120 170 B

The test procedure was followed as described above, wherein: 25 a * The relative desulfurization and hydrogenation of cyclohexene activities were determined at 325 ° C.

B = Relative dedusting activity was determined at 375 ° C.

Q 8403739, * R 7011 (R) 14

Example IX

100 g of a preformed alumina support (internal surface 250 m2 / g, pore volume 0.64 ml / g, 1.5 mm extrude) was impregnated with 4.9 g basic zinc carbonate (Zn (0 ^ 2 ^ 3) dissolved in 70 ml of a 25% aqueous ammoniacal solution (pH = 12) After filtering off the excess liquid, 55 ml of the solution were found to have been absorbed The impregnated catalyst support was dried for 16 hours at 120 ° C and calcined for 2 hours at 400eC (heating rate «5 ° C / min.) 10 The zinc content was now 2.65 wt.% ZnO. Of the impregnated and calcined support, 35 g was now impregnated with 19.3 ml of a nickel complex-containing solution, prepared as described in Example 1A (0.1248 g NiO / ml), supplemented with demineralized water to 45 ml and dissolved therein 11.8 g ammonium heptamolybdate. 33 ml of this solution absorbed by the pretreated catalyst support.

After drying at 75 ° C for 16 hours and calcining at 400 ° C for 2 hours (heating rate = 5 "C / min.), The finished catalyst contained 4.0% NiO, 16.1% MOO3 and 2.1% ZnO.

*

The activities obtained using the test procedure described above were relative to

25 Ref. A: RGA (HDS) 185%; RGA (HDN) 160%; RGA (HYD) 170% (see also the conditions specified in Examples V-VIII).

O 8403739 j

Claims (9)

A method according to claim 1, characterized in that the pH is between 11.0 and 12.5. A method according to claims 1 or 2, characterized in that the ammoniacal metal solution with which it is impregnated does not contain anions derived from strong mineral acids. 4. Process according to claim 3, characterized in that predominantly carbonate and / or hydroxyl ions are present as anions in the ammoniacal metal solution. Process according to claim 4, characterized in that the ammoniacal metal solution is prepared by dissolving finely divided Group VIII metal in an ammonium carbonate solution in ammonia, while passing through an oxygen-containing mixture. A method according to claim 1, characterized in that the Group VlII metal is nickel or cobalt. A method according to claim 1, characterized in that the group VI metal is molybdenum or tungsten. 8403739 \ • A \% R 7011 (R) 8. Catalyst containing an oxide and / or sulfide, derived from a Group VI and Group VIII metal, and a transition alumina, characterized in that the catalyst is practically free of anions derived from strong acids before calcination. Catalyst according to Claim 8, characterized in that it contains predominantly non-polymeric molybdates after calcination. Process for treating hydrocarbons with hydrogen at an elevated temperature and optionally elevated pressure in the presence of a catalyst, characterized in that the catalyst, as described in any one of the preceding claims, is used. 8403739